Hedge trimmer

ABSTRACT

A hedge trimmer has a housing. A blade bar projects forwards from the housing along a longitudinal axis. An electric drive motor drives the blade bar. At least one battery supplies the drive motor with electrical energy. The blade bar, the drive motor and the battery are mounted on the housing. The hedge trimmer has a top handle arranged above a center of gravity of the hedge trimmer, and a rear handle arranged behind the hedge-trimmer center of gravity. The battery is arranged on the housing at least mainly in front of the rear handle.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of German Patent Application No. DE10 2006 018 072.0, filed Apr. 10, 2006, which is hereby incorporated byreference.

BACKGROUND

The present invention relates to a hedge trimmer having a housing, onwhich a blade bar projects forward from the housing along a longitudinalaxis, an electric drive motor for driving the blade bar and at least oneelectric energy store for supplying the drive motor with electricalenergy are mounted, having a top handle arranged above a center ofgravity of the hedge trimmer, and having a rear handle arranged behindthe hedge-trimmer center of gravity.

Hedge trimmers serve to trim hedges or to cut back bushes or strongstalky plants. Motor-operated hedge trimmers are driven either by aninternal combustion engine or by an electric motor. Hedge trimmersdriven by electric motor have hitherto normally been mains-operated, andtherefore the electrical energy is fed via a cable. This restricts thehandling of such hedge trimmers and in addition involves a safety risk,since the cable can be severed inadvertently.

Hedge trimmers having an electric-motor drive and an electric energystore mounted on the housing of the hedge trimmer have likewise beenknown for years. This type of hedge trimmer has hitherto beenproblematic with regard to overall weight, with regard to the workingtime available with one charge, and with regard to handling.

For this reason, such hedge trimmers have hitherto only been used in thehobby sector. In recent years, however, the energy density of availableelectric energy stores has greatly increased, in particular in the caseof lithium-based batteries. For this reason, the aim is also to usehedge trimmers of the generic type in the “professional sector”.

DE-C 1 223 443 discloses a hedge trimmer in which a rear part of thehousing is designed as a handle which accommodates an interchangeablebattery set.

EP 0 599 550 P1 likewise discloses a hedge trimmer of the generic typein which a safety locking mechanism is implemented.

EP 0 374 600 B1 discloses a hedge trimmer driven by a battery that islocated beneath the rear handle.

A common feature of these implements, as well as of the implements fromthe “hobby sector” which are otherwise available on the market, is thatthe battery is arranged on a rear or bottom section of the housing.

Further, DE 199 26 375 A1 discloses a mains-independent hedge trimmer,the rear handle thereof being pivotably mounted on the housing.

BRIEF SUMMARY

Against the above background, it would be desirable to provide a hedgetrimmer of the generic type which offers ease of handling.

Described below is a hedge trimmer that, in one implementation, has anenergy store or battery arranged on the housing at least mainly in frontof the rear handle.

This design ensures that the hedge trimmer has good “balance” overall.Therefore fatigue-free operation even for a prolonged period ispossible.

In addition, the rear handle can be configured or designed in anydesired manner within wide limits.

In this connection it should be noted that, within the scope of thepresent application, a longitudinal direction is generally a directionparallel to the longitudinal axis of the blade bar. A lateral directionis a direction transversely, in particular approximately at rightangles, to the longitudinal direction, and to be precise, approximatelyin the horizontal direction. A height direction is likewise a directionapproximately at right angles to the longitudinal direction, and to beprecise, approximately in the vertical direction.

The expressions “front” and “rear” generally relate to the longitudinaldirection, “front” being where the blade bar is. The expressions “above”and “below” relate to the height direction.

These specifications of location, however, are only intended to servefor simplified description of the relative position of the components ofthe hedge trimmer according to the invention, to be precise in a normalhorizontal working position of the hedge trimmer. In addition, however,the expressions are not to be understood restrictively.

The energy store is preferably arranged on the housing in front of thedrive motor as viewed in the longitudinal direction.

This configuration enables a very good distribution of weight or verygood balance to be achieved overall.

For effective arrangement of the blade bar on the housing, a couplingbetween the blade bar and the electric drive motor inside the housing isoften shifted rearwards as viewed in the longitudinal direction.Therefore, in the arrangement of the energy store in front of the drivemotor, the available construction space is also readily utilized.

According to a further preferred embodiment, the energy store isarranged on the housing in an overlapping manner with the drive motor asviewed in the height direction. Here, too, good balance is achieved.

The energy store is preferably arranged on the housing at least partlyabove the drive motor. This permits possibly easier interchangeabilityof the energy store.

As an alternative to this, it is possible to arrange the energy store onthe housing at least partly below the drive motor.

According to a further preferred embodiment, the energy store isarranged on the housing at least partly in an overlapping manner withthe drive motor as viewed in the lateral direction.

Here, too, it is possible to achieve a good distribution of weight andthus good “balance.” Furthermore, it is possible for the housing to beof compact design in the height direction.

It is especially advantageous in this case if the energy store isarranged on the housing laterally next to the drive motor.

According to a further preferred embodiment, the energy store isarranged on the housing behind the drive motor as viewed in thelongitudinal direction.

Here, too, a good distribution of the weight can be realized.

Furthermore, it is advantageous overall if the energy store has twosections which are arranged approximately symmetrically with respect tothe drive motor.

In this embodiment, the energy store can certainly consist of one piecebut can have two sections, such as legs for example, which extendapproximately symmetrically with respect to the drive motor. However, itis also possible to mount two energy stores on the housing, these energystores being separate from one another and being arranged symmetricallywith regard to the drive motor.

The symmetry in this case may relate to the height direction. However,in order to achieve a type of construction that is compact in the heightdirection, it is especially preferred if the two sections are arrangedlaterally next to the drive motor.

It is generally also possible for the two sections not to be arrangedsymmetrically relative to the drive motor.

According to a further embodiment preferred overall, the energy store isarranged on the housing obliquely with respect to the longitudinal axis.

In this embodiment, a type of construction that is compact in the heightdirection can likewise be achieved.

It is also especially advantageous for the same reason if the drivemotor has a motor shaft which is arranged obliquely with respect to thelongitudinal axis.

In the present connection, “obliquely” is meant to refer to an anglegreater than 0° and less than 90°, in particular an angular range of 15to 80°.

Due to the oblique arrangement of the drive motor, a compact type ofconstruction can be achieved in the height direction, it also beingpossible to achieve good balance.

It is generally also possible to arrange the drive motor parallel to thelongitudinal axis.

It is especially advantageous in the oblique or parallel orientation ofthe drive motor if the motor shaft is connected to the blade bar via anangular gear unit.

It is advantageous overall if the energy store is arranged on thehousing on the whole or entirely in front of the rear handle as viewedin the longitudinal direction.

In this embodiment, very good balance can be achieved even in the caseof a comparatively large and comparatively heavy battery.

Furthermore, it is advantageous if the energy store has an energy-storecenter of gravity, and if the energy store is arranged on the housing insuch a way that the energy-store center of gravity is arranged behindthe top handle as viewed in the longitudinal direction. The balance canbe further improved by this measure.

According to a further preferred embodiment, the energy store isarranged on the housing on the whole behind the top handle as viewed inthe longitudinal direction.

In this way, the weight of the energy store with respect to the tophandle helps to provide a counterbalance to the blade bar.

It is also advantageous overall if the energy store has an energy-storecenter of gravity, and if the energy store is arranged on the housing asviewed in the lateral direction in such a way that the energy-storecenter of gravity is at a distance of not more than 20% of the overallwidth of the housing from a center-of-gravity longitudinal axis whichpasses through the hedge-trimmer center of gravity.

This measure ensures that the battery also helps to provide good balancein the lateral direction of the hedge trimmer.

Furthermore, it is advantageous if the energy store is interchangeable,and if the housing has at least one mechanical and/or electricalinterface for at least one energy store.

It is certainly also conceivable to integrate an energy store entirelyin the housing and to merely provide an interface on the outside on thehousing for charging the energy store. However, the interchangeabilityof the energy store ensures that the hedge trimmer can be operated bymeans of a plurality of energy stores even for prolonged periods.

It is especially advantageous in this case if the interface on thehousing is accessible from above, such that an energy store can beconnected to the interface essentially from above.

This means that the battery can easily be inserted and removed.

It is also possible for the interface on the housing to be accessiblefrom the front, in particular obliquely from the front, or from theside, such that an energy store can be connected to the interfaceessentially from the front, in particular obliquely from the front, orfrom the side.

This also ensures that the energy store can be easily inserted andremoved.

It is especially advantageous here if the housing for accommodating theenergy store has a receptacle in which the interface is arranged.

In this case, the energy store forms fewer disturbing contours in theinserted state and can be accommodated at least partly in thereceptacle. In addition, the interface can be better protected fromenvironmental load if it is arranged inside the receptacle.

Furthermore, an advantageous embodiment consists in the fact that thetop handle is connected to the housing via at least one handle webangled relative to the top handle, the handle web engaging the housingin a region below the hedge-trimmer center of gravity.

Due to this measure, it is also possible to optimally adapt the positionof the top handle as viewed in the longitudinal direction to theposition of the other components of the hedge trimmer, in particular inorder to achieve good balance. Furthermore, this permits easy handling,such that the hedge trimmer can also be taken hold of from the side,that is to say on the handle web.

It is likewise advantageous if a handle axis of the rear handle isoriented within the range of −30° to +30°, in particular −20° to +20°,with respect to the longitudinal axis.

Although it is generally conceivable for the handle axis to be offsetlaterally from the longitudinal axis, it is preferred if the handle axisis disposed at a fixed angle or is pivotable relative to thelongitudinal axis in the height direction within this angular range.

Easy handling can be achieved overall with an arrangement of the handleaxis within the angular range.

The rear handle is preferably pivotably mounted on the housing about apivot axis which is oriented transversely to the longitudinal axis.

In this embodiment, the hedge trimmer can be optimally adapted to thepreferred posture of an operator.

The pivot axis in this case preferably runs in the lateral direction.

According to a further preferred embodiment, the rear handle isrotatably mounted on the housing about an axis which is orientedessentially parallel to the longitudinal axis or the associated handleaxis.

In this embodiment, an ergonomic position of the hedge trimmer can alsobe achieved when guiding the hedge trimmer in a vertical plane.Fatigue-free work is generally possible. The axis of rotation may beoriented parallel to the longitudinal axis. However, the axis ofrotation may also be angled relative to the longitudinal axis within therange of up to about ±20°.

Rotatability can be possible, for example, from −90° to +90° relative tothe height direction. However, a greater or a more restricted angularrange with respect to this rotatability is also conceivable.

In addition, rotatability or a pivoting capacity of the rear handle canbe achieved in a simple manner in terms of design if the energy store isarranged on the whole in front of the rear handle.

It is also preferred overall if the drive motor and the energy store arearranged on the housing in such a way that the hedge trimmer, if it isfreely held at the top handle, assumes a position of equilibrium inwhich the longitudinal axis encloses an equilibrium angle a within therange of −30°≦α≦+30° with the horizontal.

This avoids a situation in which the blade bar swings upwards ordownwards if a person lets go of the rear handle and the hedge trimmeris consequently only held at the top handle. This could even lead to asafety risk if the blade bar is still running on after letting go of therear handle.

It should be noted here that the hedge trimmer according to theinvention preferably has an actuating means on both the top and the rearhandle, the hedge trimmer only being put into operation when bothactuating means are actuated.

Preferably, the center of gravity of the energy store is arranged abovethe blade bar.

This allows a bottom side of the housing to be arranged flush with theblade bar so that the housing and the energy store, respectively, do notform a disturbing contour for the regular operation of the hedgetrimmer.

It goes without saying that the abovementioned features and the featuresstill to be explained below can be used not only in the respectivelyspecified combination but also in other combinations or on their ownwithout departing from the scope of the present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Exemplary embodiments of the invention are shown in the drawing anddescribed in more detail below. In the drawings:

FIG. 1 shows a perspective view, partly cut away at the housing, of anembodiment of a hedge trimmer according to the invention obliquely fromthe rear;

FIG. 2 shows a schematic side view of hedge trimmers according to theinvention in different positions of equilibrium;

FIG. 3 shows a schematic side view of a further embodiment of a hedgetrimmer according to the invention;

FIG. 4 shows a schematic side view of a further embodiment of a hedgetrimmer according to the invention;

FIG. 5 shows a schematic plan view of a further embodiment of a hedgetrimmer according to the invention;

FIG. 6 shows a schematic view of a further embodiment of a hedge trimmeraccording to the invention from below;

FIG. 7 shows a schematic view of a further embodiment of a hedge trimmeraccording to the invention from below; and

FIG. 8 shows a schematic side view of a further embodiment of a hedgetrimmer according to the invention.

DETAILED DESCRIPTION

A first embodiment of a hedge trimmer according to the invention isdesignated overall by 10 in FIG. 1.

The hedge trimmer 10 has a housing 12 extending generally along alongitudinal axis L. Mounted on or to the housing 12 is a blade bar 14,which extends along the longitudinal axis L. Furthermore, an electricdrive motor 16 and an electric energy store 18 in the form of arechargeable battery are arranged on or in the housing 12.

The energy store 18 has cells with a high energy density of, forexample, at least 100 Wh/kg. The energy store 18 may be designed on alithium basis, for example as a lithium ion battery, lithium polymerbattery, etc., or on another or comparable basis. Furthermore, it goeswithout saying that the energy store may consist of a plurality ofcells, the individual voltages of which add up on account of a seriesconnection. A parallel connection of such individual cells is alsopossible. Furthermore, the energy store 18 preferably contains aninternal protective circuit which disconnects the energy store, forexample before a low charge or overcharge. Charging electronics may alsobe contained in the protective circuit.

Furthermore, a top handle 20 and a protective shield 22 are fixed to thehousing 12. The protective shield 22 is arranged obliquely in front ofthe top handle 20 and serves to protect the hand holding the top handle20 from branches or the like.

Furthermore, a rear handle is provided on the housing 12. The rearhandle is oriented approximately parallel to the longitudinal axis L,whereas the top handle 20 is oriented transversely thereto. The tophandle 20 is connected to the housing 12 via a left-hand and aright-hand lateral gripping web 26, to be precise in the region of thebottom ends of the gripping webs 26.

Serving to explain the relative position of the above-described elementsis a coordinate system which is depicted in FIG. 1 and is used below asfollows. In the coordinate system, an x axis is oriented generallyparallel to the longitudinal axis L. A y axis is oriented at rightangles to the x axis in the height direction and thus extends verticallyin the horizontal arrangement of the x axis. The z axis is oriented inthe lateral direction and thus extends to the left and right withrespect to the x axis. Furthermore, it is assumed that the blade bar 14is arranged at the front and the rear handle 24 is arranged at the rear,this only being a definition and not being intended to be seenrestrictively.

In the present exemplary embodiment, the origin of the above-describedcoordinate system is placed at a suspension point 28 on the top handle20. Positive x values extend rearwards starting from here. Positive yvalues extend downwards starting from here.

The hedge trimmer 10 of FIG. 1 has an overall center of gravity which isdesignated by 30 in FIG. 1. In the case shown, the center of gravity 30lies in front of the origin 28 of the coordinate system at −x_(SH). Thismeans that the hedge trimmer 10, when it is freely held at the tophandle, tilts slightly downwards with the blade bar 14. In the positionof equilibrium, the center of gravity 30 then lies below the suspensionpoint 28 (=origin of coordinate system) of the top handle 20. This isshown in FIG. 2 for three different designs of the hedge trimmer 10. Ifthe center of gravity 30 a lies directly below the suspension point 28 awhen the hedge trimmer 10 is oriented horizontally, a horizontalposition of equilibrium is obtained. If the center of gravity 30 b liesbehind the suspension point 28 b, a position of equilibrium pointingobliquely upwards is obtained, an equilibrium angle α_(b) being setbetween the longitudinal axis L_(b) and the horizontal H. If the centerof gravity 30 c lies in front of the suspension point 28 c, a positionof equilibrium is obtained in which the blade bar 14 c is inclineddownwards and assumes an equilibrium angle α_(c) with the horizontal H.

Again referring to FIG. 1, the electric drive motor 16 and the electricenergy store 18 are arranged on the housing 12 in such a way that thehedge trimmer, if it is held at the suspension point 28, assumes aposition of equilibrium in which the equilibrium angle α is within therange of −30°≦α≦+30°. The respective limit angles are shown in FIG. 2.

The electric energy store has a center of gravity 32. The electric drivemotor 16 has a center of gravity 34, and the blade bar 14 has a centerof gravity 36.

The following indication of relative positions of the individualelements is intended to relate generally to the position of therespective center of gravity, unless indicated otherwise.

In the hedge trimmer 10 of FIG. 1, a stable position of equilibrium isachieved by the energy store 18 being arranged in front of the drivemotor 16, that is to say x_(SE)<x_(SM), where SE relates to the centerof gravity of the energy store and SM relates to the center of gravityof the motor.

Furthermore, it can be seen in the illustration of FIG. 1 that thecenter of gravity 30 lies in front of the suspension point 28, sincex_(SH) (SH stands for center of gravity of hedge trimmer) lies withinthe negative x range.

Both the drive motor 16 and the energy store 18 lie in front of the rearhandle 24. Furthermore, in the embodiment in FIG. 1, the energy store 18and the drive motor 16 lie behind the suspension point 28. The center ofgravity 32 of the energy store 18 lies above the blade bar 14. To beexact, the energy storage 18 lies completely above the blade bar 14(with reference to a horizontal attitude of the edge trimmer.

Further embodiments of hedge trimmers according to the invention aredescribed below, the general construction and general functioning ofwhich correspond to the hedge trimmer 10 of FIG. 1. The same elements orelements corresponding to one another are therefore provided with thesame reference numerals. Furthermore, the above description is intendedto be generally applicable in the same manner to the followingembodiments, and therefore only the differences are dealt with below.

An alternative embodiment of a hedge trimmer according to the inventionis designated overall by 10′ in FIG. 3. The hedge trimmer 10′ isdesigned such that the housing 12 is of generally flat construction inthe height direction y.

In this case, provision is made for the drive motor 16 to be orientedobliquely to the longitudinal axis L. To be more precise, the drivemotor 16 has a motor shaft 38 which encloses a motor shaft angle β withthe longitudinal axis L. The angle β generally lies within the range of0°<β≦90°, preferably within the range of 5°≦β≦80°, and in particularwithin a range 0°<β≦50°.

One end of the motor shaft 38 is coupled to an angular gear unit 40,which is connected to an eccentric drive 42 for driving the blade bar14.

The inclination of the electric drive motor 16 means that the housing 12can be of smaller construction in the height direction y.

It is also shown in FIG. 3 that the housing 12 has an opening 44 in arear region, the rear handle 24 being formed above the opening 44. Ahand grasping the rear handle 24 consequently reaches into the housingopening 44. An operating means in the form of a switch 46 is arranged onthe inner circumference of the housing 44.

Furthermore, the housing 12 has a receptacle 50 for an energy store 18,an electrical interface 48 for the electrical connection of the energystore 18 to control electronics (not shown) arranged in the housing 12being provided at the base of the receptacle 50.

The interface 48 may also contain mechanical interface components, suchas latching components for example.

The receptacle 50 is in this case provided on the housing in such a waythat the energy store 18 is oriented obliquely to the longitudinal axisL and is arranged obliquely above the drive motor 16. In other words,the center of gravity 32 of the energy store 18 is arranged behind buthigher than the center of gravity 36 of the drive motor 16. Inprojection, the housings of drive motor 16 and energy store 18 overlapin both the height direction y and the longitudinal direction x.

In a top region of the housing 12, the receptacle 50 has an opening viawhich the energy store 18 can be inserted. The insertion direction isshown at 52.

Also shown in FIG. 3 is an energy store 18′ which is arranged obliquelybelow the drive motor 16. The energy store 18′ may be provided as analternative to or in addition to the energy store 18. A correspondingreceptacle 50′, with an interface 48′, may be advantageously providedfor the energy store 18′. In this case, the interface 48′ is accessiblefrom the front, as shown by an arrow 52′.

A further alternative embodiment of a hedge trimmer according to theinvention is designated overall by 10″ in FIG. 4.

In the hedge trimmer 10″, the drive motor 16 is likewise arrangedobliquely, as in the hedge trimmer 10′ of FIG. 3. The battery 18,however, is arranged completely behind the drive motor 16 and isoriented, for example, in the height direction y. In a correspondingmanner, the receptacle 50 is oriented in the height direction y and anenergy store 18 is inserted into the receptacle 50 in the heightdirection y (arrow 52).

Apart from that, the construction of the hedge trimmer 10″ correspondsto that of the hedge trimmer 10′.

In addition to this, however, provision is made for the rear handle 24″to be pivoted (disposed at a fixed angle) or to be pivotable relative tothe housing 12, to be precise about a pivot axis 54 which is oriented inthe lateral direction z. The pivoting direction is shown at 56. Thepivot angle is designated by γ.

In general it is possible to pivot the rear handle 24 within a range of−30°≦γ≦30°, in particular from −20° to +20° or from 0° to +30°, to beprecise with regard to the longitudinal direction x.

A further alternative embodiment of a hedge trimmer according to theinvention is designated overall by 10′″ in FIG. 5.

In the hedge trimmer 10′″, the drive motor 16 is arranged as in thehedge trimmers 10′ and 10″. However, the energy store in the hedgetrimmer 10′″ has two sections 18A, 18B which are arranged in the lateraldirection z on opposite sides of the drive motor 16. Here, the energystore sections 18A, 188B are preferably arranged symmetrically withrespect to the drive motor 16. The energy store sections 18A, 18B may bepart of a single energy store, which has a U shape for example. In thiscase, the U legs would form the energy store sections 18A, 18B.

However, it is also possible for the energy store sections 18A, 18B toeach be formed by a separate energy store (for example in the form of arespective battery with separate protective circuit).

In FIG. 5, it is shown at 58 that it is possible for the rear handle24′″ to be mounted on the housing 12 in a rotatable manner about an axiswhich is oriented parallel to the longitudinal axis L or the handle axisof the rear handle (which is possibly pivoted).

In this case, either the entire rear handle 24′″ may be rotatable aboutthe axis, or only the section of the rear handle 24′″ which is actuallygrasped by the hand may be rotatable.

Due to the rotatability of the rear handle 24′″, in particular workoverhead or in a perpendicular orientation of the hedge trimmer issimplified.

It should generally be noted that a large degree of freedom with regardto the configuration and construction of the rear handle 24 is possibledue to the arrangement of the energy store 18 in front of the rearhandle 24. This applies to both the rotatability and the possiblepivoting capacity of the rear handle 24.

A further alternative embodiment of a hedge trimmer according to theinvention is designated overall by 10 ^(IV) in FIG. 6.

In FIG. 6, the eccentric drive 42 for driving the blade bar 14 is shownin greater detail. It can be seen that the eccentric drive has a gear62, which is driven by a pinion 60. The pinion 60 may be fixed, forexample, to the motor shaft 38 of the drive motor 16. However, thepinion 60 may also be part of the angular gear unit 40, as shown inFIGS. 3 and 4.

A reduction ratio can be set by the combination of the pinion 60 and thegear 62, such that the drive motor 16 can be operated at relatively highspeed. In this way, the drive motor 16 can be of compact design overall.

Also shown in FIG. 6 is an energy store 18, which is arranged in frontof the drive motor 16 as viewed in the longitudinal direction x.

Also shown in FIG. 6 is the center of gravity 32 of the energy store 18.The center of gravity 32 is at a lateral distance 64 from thelongitudinal axis L of the hedge trimmer 10 ^(IV), the longitudinal axisL passing through the center of gravity 30 of the hedge trimmer 10^(IV).

The value of the distance 64 is less than 20% of the overall width B ofthe housing 12 of the hedge trimmer 10 ^(IV), such that good balance canalso be achieved in the lateral direction.

A further alternative embodiment of a hedge trimmer according to theinvention is designated overall by 10 ^(V) in FIG. 7.

The hedge trimmer 10 ^(V) corresponds to the hedge trimmer 10 ^(IV) inFIG. 6, a belt drive being provided instead of the pinion 60 and thegear 62, which belt drive has a first belt pulley 68 which is coupled tothe motor shaft 38 of the drive motor 16. Furthermore, the belt drivehas a second belt pulley 70 which is coupled to the eccentric drive 42.A corresponding belt is shown at 72. A reduction ratio can also beachieved with the belt drive 68, 70, 72. It goes without saying that thefirst belt pulley 68 can also be connected to the angular gear unit 40instead of the motor shaft 38.

A further alternative embodiment of a hedge trimmer according to theinvention is designated overall by 10 ^(VI) in FIG. 8.

It is shown in FIG. 8 that the motor shaft 38 of the electric drivemotor 16 is not directly connected to the pinion 60. Rather, in the caseof the hedge trimmer 10 ^(VI), a slip clutch 76 is arranged between themotor shaft 38 and the pinion 60 (or the first belt pulley 68). The slipclutch 76 serves to avoid an excessive motor current if the blade bar 14is suddenly obstructed, for example when engaging on a branch that istoo thick or on a woody branch.

In the hedge trimmer 10 ^(VI), the energy store 18 is arranged in frontof the drive motor 16, as in the hedge trimmer 10 of FIG. 1.

Furthermore, it is shown in FIG. 8 that the rear handle 24 is orientedin a handle axis G. The handle axis G runs approximately parallel to thelongitudinal axis L or at an acute angle to it, the handle axis G andthe longitudinal axis L enclosing a handle angle (comparable to thehandle angle γ in FIG. 4), which can be within the range of −30°≦γ≦30°.In the embodiment shown, the angle γ is markedly smaller than 5°.

It goes without saying that the various modifications which are shown inthe different embodiments of hedge trimmers in FIGS. 3 to 8 can be usedin any desired combination. The illustration of individual features withregard to one of the embodiments is in no way intended to have arestrictive effect with regard to the other embodiments. The otherembodiments may also each be provided with the features shown in onlyone other embodiment.

1. A hedge trimmer comprising: a housing; a blade bar projecting forward from the housing along a longitudinal axis; an electric drive motor for driving the blade bar coupled to the housing; at least one battery for supplying the drive motor with electrical energy coupled to the housing; and a top handle arranged above a center of gravity of the hedge trimmer, and having a rear handle arranged behind the hedge-trimmer center of gravity, wherein the battery is arranged on the housing at least mainly in front of the rear handle.
 2. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing in front of the drive motor as viewed in the longitudinal direction.
 3. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing in an overlapping manner with the drive motor as viewed in the height direction.
 4. The hedge trimmer according to claim 3, wherein the battery is arranged on the housing at least partly above the drive motor.
 5. The hedge trimmer according to claim 3, wherein the battery is arranged on the housing at least partly below the drive motor.
 6. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing at least partly in an overlapping manner with the drive motor as viewed in the lateral direction.
 7. The hedge trimmer according to claim 6, wherein the battery is arranged on the housing laterally next to the drive motor.
 8. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing behind the drive motor as viewed in the longitudinal direction.
 9. The hedge trimmer according to claim 1, wherein the battery has two sections which are arranged approximately symmetrically with respect to the drive motor.
 10. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing obliquely with respect to the longitudinal axis.
 11. The hedge trimmer according to claim 1, wherein the drive motor has a motor shaft which is arranged obliquely with respect to the longitudinal axis.
 12. The hedge trimmer according to claim 11, wherein the motor shaft is connected to the blade bar via an angular gear unit.
 13. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing on the whole in front of the rear handle as viewed in the longitudinal direction.
 14. The hedge trimmer according to claim 1, wherein the battery has an battery center of gravity, and wherein the battery is arranged on the housing in such a way that the battery center of gravity is arranged behind the top handle as viewed in the longitudinal direction.
 15. The hedge trimmer according to claim 1, wherein the battery is arranged on the housing on the whole behind the top handle as viewed in the longitudinal direction.
 16. The hedge trimmer according to claim 1, wherein the battery has an battery center of gravity, and wherein the battery is arranged on the housing as viewed in the lateral direction in such a way that the battery center of gravity is at a distance of not more than 20% of the overall width of the housing from a center-of-gravity longitudinal axis which passes through the hedge-trimmer center of gravity.
 17. The hedge trimmer according to claim 1, wherein the battery is interchangeable, and wherein the housing has at least one of a mechanical and an electrical interface for at least one energy store.
 18. The hedge trimmer according to claim 17, wherein the interface on the housing is accessible from above, such that a battery can be connected to the interface essentially from above.
 19. The hedge trimmer according to claim 17, wherein the interface on the housing is accessible from the front, in particular obliquely from the front, such that a battery is connected to the interface essentially from the front.
 20. The hedge trimmer according to claim 17, wherein the interface on the housing is accessible obliquely from the front.
 21. The hedge trimmer according to claim 17, wherein the interface on the housing is accessible from the side, such that a battery is connected to the interface essentially from the side.
 22. The hedge trimmer according to claim 17, wherein the housing for accommodating the energy store has a receptacle in which the interface is arranged.
 23. The hedge trimmer according to claim 1, wherein the top handle is connected to the housing via at least one handle web angled relative to the top handle, the handle web engaging the housing in a region below the hedge-trimmer center of gravity.
 24. The hedge trimmer according to claim 1, wherein a handle axis of the rear handle is oriented within the range of −30° to +30° with respect to the longitudinal axis.
 25. The hedge trimmer according to claim 1, wherein the rear handle is pivotably mounted on the housing about a pivot axis which is oriented transversely to the longitudinal axis.
 26. The hedge trimmer according to claim 1, wherein the rear handle is rotatably mounted on the housing about an axis which is oriented essentially parallel to the longitudinal axis.
 27. The hedge trimmer according to claim 1, wherein the rear handle is rotatably mounted on the housing about an axis which is oriented essentially parallel to the associated handle axis.
 28. The hedge trimmer according to claim 1, wherein the drive motor and the battery are arranged on the housing in such a way that the hedge trimmer, if it is freely held at the top handle, assumes a position of equilibrium in which the longitudinal axis encloses an equilibrium angle ax within the range of −30°≦α≦+30° with the horizontal.
 29. The hedge trimmer according to claim 1, wherein the center of gravity of the battery is arranged above the blade bar.
 30. The hedge trimmer according to claim 29, wherein the battery is arranged completely above the blade bar.
 31. A hedge trimmer comprising: a housing; a blade bar positionable to project forward from the housing along a longitudinal axis; an electric drive motor for driving the blade bar; at least one battery for supplying the drive motor with electrical energy; a top handle coupled to the housing; and a rear handle arranged behind a hedge-trimmer center of gravity; wherein the battery is arranged on the housing in front of the rear handle, and wherein the center of gravity of the battery is arranged generally above the blade bar.
 32. The hedge trimmer according to claim 31, wherein the battery is arranged on the housing in front of the drive motor as viewed in the longitudinal direction.
 33. The hedge trimmer according to claim 31, wherein the battery is arranged on the housing behind the drive motor as viewed in the longitudinal direction.
 34. The hedge trimmer according to claim 31, wherein the battery has a battery center of gravity, and wherein the battery is arranged on the housing in such a way that the battery center of gravity is arranged behind the top handle as viewed in the longitudinal direction.
 35. The hedge trimmer according to claim 31, wherein the battery is interchangeable, and wherein the housing has at least one of a mechanical and at least one of an electrical interface for at least one battery.
 36. The hedge trimmer according to claim 35, wherein the interface on the housing is accessible from above, such that an battery can be connected to the interface essentially from above.
 37. The hedge trimmer according to claim 35, wherein the interface on the housing is accessible from the side, such that an battery is connected to the interface essentially from the side. 